SUMMARY/ABSTRACT The objective of this proposal is to deploy standard as well as innovative diagnostic tools in order to investigate what proportion of severe febrile illness (SFI) in northern Tanzania is attributable to emerging zoonotic viral pathogens. Fever is among the most common reasons for seeking health care in less developed countries, yet up to half of patients hospitalized with fever in sub-Saharan Africa may go without a laboratory- confirmed diagnosis?this represents a serious knowledge gap that hinders disease prevention efforts. Prior research in northern Tanzania has revealed that animal-borne bacterial infections are a common cause of SFI, perhaps reflecting the effects of close interaction between humans, livestock and wildlife in many parts of sub- Saharan Africa. Yet the impact of animal-borne viral infections, such as henipa-, bunya-, corona- and reoviruses, remains unknown. An enhanced understanding of whether and which of these high-consequence viral pathogens are causing SFI is fundamental to the prevention and control of severe infectious diseases in sub-Saharan Africa and to the global health security agenda of the United States and other G7 countries. To these ends, this career development award proposes to utilize well-characterized archived blood specimens from prior fever etiology research in northern Tanzania in order to undertake the following SPECIFIC AIMS: SPECIFIC AIM 1?Establish the prevalence of exposure to zoonotic viral pathogens by performing antibody evaluations of serum from patients with SFI and from previously enrolled community-dwellers. SPECIFIC AIM 2? Establish the proportion of SFI cases with detectable viremia from select zoonotic pathogens by performing real-time polymerase chain reaction (PCR) assays on SFI patient blood samples. SPECIFIC AIM 3?Achieve enhanced viral pathogen detection and discover new viral pathogens by interrogating SFI blood samples with hybridization enrichment next-generation sequencing technology. The requisite laboratory work to achieve these SPECIFIC AIMS will be conducted at Duke-National University of Singapore Graduate Medical School (Duke-NUS) under the direction of the Candidate and the Director of the Duke-NUS Program in Emerging Infectious Disease, Lin-Fa Wang, PhD (K23 Co-Mentor), and Duke University/Duke-NUS faculty, Greg Gray, MD, MPH (K23 Co-Mentor). De-identified serum, plasma and whole blood will be utilized for these aims. These well-characterized blood specimens represent nearly 1500 patients enrolled in two febrile illness research cohorts conducted in northern Tanzania by K23 Primary Mentor, John Crump, MB ChB, MD: International Co-Studies of AIDS-Associated Co-Infections (U01 AI062563), a comprehensive fever etiology study; and The Impact and Social Ecology of Bacterial Zoonoses in Northern Tanzania (R01TW009237), an epidemiologic risk factor analysis on zoonotic causes of SFI. The Candidate, Matthew Rubach, MD, is a board-certified medical microbiologist and infectious disease physician. Dr. Rubach was stationed full-time in Moshi, Tanzania 2012-2014. He has engaged successfully in clinical research on febrile illness and the epidemiology of bacterial zoonotic infections under the mentorship of Dr. Crump and in the context of Dr. Crump's productive zoonoses research program, comprised of over 20 collaborating scholars from multiple disciplines. This institutional environment in Tanzania, the excellent mentorship team as well as directed coursework through the London School of Hygiene & Tropical Medicine MSc Epidemiology distance learning program will collectively enable the Candidate to achieve the following TRAINING OBJECTIVES: TRAINING OBJECTIVE 1?To develop further expertise in epidemiologic research, clinical research study design, and quantitative analysis (Drs. Crump & Gray; coursework). TRAINING OBJECTIVE 2 ? To develop further expertise in the epidemiology of zoonotic infections (Drs. Crump & Gray; coursework). TRAINING OBJECTIVE 3?To develop further technical expertise in innovative diagnostic microbiology through mentored clinical research that utilizes novel pathogen detection and pathogen discovery laboratory techniques (Dr. Wang). Ultimately, Dr. Rubach aspires to improve infectious disease diagnostic capacity in resource-limited settings by conducting relevant clinical research as Duke University faculty stationed full-time at the KCMC- Duke University Health Research Collaboration in Moshi, Tanzania. This early career award will equip Dr. Rubach with technical expertise in innovative diagnostics that will differentiate him from his Primary Mentor and will enable Dr. Rubach to develop an independent research track with novel approaches to infectious disease diagnostics for clinical and epidemiologic research. Through the mentorship and training objectives in this proposal, Dr. Rubach will emerge with a highly unique skillset that bridges world-class infectious disease epidemiology research in the field with state-of-the-art technical expertise in diagnostic microbiology. As such, he will be well positioned to seek R01 funding support for further studies on the diagnosis, management and epidemiology of zoonotic and non-zoonotic causes of SFI.